NuVasive said it expects about $147 million in revenue in the third quarter. The company reported $154.4 million in revenue in the second quarter and had said it expected similar results in the third quarter. NuVasive said its revenue was hurt by growing discounts from competitors and from an increase in coverage delays and denials from health insurers.

Analysts expected the company to report $153.6 million in revenue in the third quarter, according to FactSet.

Shares of NuVasive dropped $5.63, or 24.9 percent, to $16.99 in late trading. The stock slipped 39 cents to $22.62 during the day.

NuVasive's new forecast implies revenue growth of about 11 percent from a year ago. The San Diego company is scheduled to report its quarterly results after the market closes on Oct. 29.